Pluggable optical transceiver is an essential building block for implementing high-speed interconnects in data centers, mobile base-stations and high-performance computing applications for connecting routers, base-band network equipment and computer processors located in separate chassis within the data centers. A typical transmission distance within a data center is around 300 meters. In this type of applications, high-speed data (10 Gb/s or higher) to be transmitted over the interconnect is converted to optical signals by the transmitter, typically based on vertical cavity surface emitting laser (VCSEL) emitting at 850 nm wavelength within the transceiver, and transmitted over multi-mode optical fibers. At the other end of the link, the signal is converted back to electrical signals by the receiver portion of another transceiver. The exponential growth of mobile data usage, cloud computing and big-data applications has led to increased demand for network equipment and high-performance computer equipment. This also drives up the demand for high-speed optical interconnects. There is therefore an increasing need for low-cost optical transceivers for implementing this type of interconnects.
Optical transceivers used in data-center applications often follow a multi-source agreement (MSA) form-factor. Small form-factor pluggable (SFP) is one such form-factor. In conventional SFP/SFP+ transceivers, the laser and the photodiode (PD) are separately packaged into metal-can packages to form a transmitter and receiver optical sub-assembly (OSA). The optics on the OSA required for optical signal coupling with external fibers are manually aligned with the laser and photodiodes within the OSA's. These sub-assemblies are subsequently soldered onto a printed circuit boards (PCB) having laser driver integrated circuit (IC), receiver IC and micro-controller assembled thereon. This assembly is then fitted into a SFP-compliant housing to form the final product. This transceiver design requires many components and a complex assembly process and therefore drives up the cost of the transceiver.